Press unloading apparatus



Dec. 29, 1959 w MQNRQE ETAL 2,918,862

PRESS UNLOADING APPARATUS Filed Oct. 30, 1956 S m m m m Wilfred 151M onroe BY William E Cooper United States Patent 2,918,862 PRESS UNLOADING APPARATUS Wilfred E. Monroe, Longview, and William F. Cooper, Kelso, Wash.; Erma N. Monroe, administratrix of said Wilfred E. Monroe, deceased, assignors to International Paper Company, New York, N.Y., a corporation of New York Application October 30, 1956, Serial No. 619,318 3 Claims. (Cl. 100-198) This invention relates to apparatus for unloading presses having a plurality of relatively movable pressure plates therein. It pertains particularly to apparatus for unloading work units such as composition boards or plywood panels from the multiopening presses employed in the manufacture of such units. v

In the manufacture of composition boards, wood particles of suitable size are mixed with resinous binder and formed into mats which are interposed between metal caul plates to form a sandwich-type work unit of substantial dimensions, for example four by eight feet. These units are accumulated in a press charger while a prior charge is being cured under heat and pressure in the press.

At the conclusion of the press cycle, the press is opened and the cured boards are ejected on the carrier cauls. They are received by a press receiver stationed adjacent the discharge end of the press. A fresh charge of work units then is pushed into the press to initiate another pressing cycle.

In this sequence, it is necessary for efficient plant operation that the press be unloaded rapidly and dependably at the proper time. This has not always been possible when prior art press unloading apparatus has been employed.

For example, in one such apparatus the incoming caul work units have been employed to push the outgoing work units a predetermined distance out of the press where they have been engaged by a feed-out apparatus. Such an arrangement has proved undependable since the work units overlap in the press when the ends of the outgoing and incoming units have not registered precisely, even though guide means have been employed for securing such registration.

Similarly, in the past the work units have been pulled out of the press by means of a puller bar mounted on the press receiver. This bar is provided with means to engage loops, T-bars or other types of projections on the leading edges of the. work units. However the necessity of providing such projections complicates the handling of the work units and introduces an element of unreliability and expense.

In still another prior art method the work units include cauls which project beyond the ends of the press. Multiple clamps then are provided for engaging the end of each caul individually to pull it out of the opened press. This method is subject to the serious disadvantage of requiring complicated apparatus including numerous clamps and of imparting undesirable stresses to the cauls since a zone is present which is not in contact with the hot plate when the press is closed.

Accordingly it is the general object of the present invention to provide press unloading apparatus which is adaptable for the positive, efficient and rapid unloading of diverse work units, particularly caul plate-fibrous mat sandwich assemblies, from multi-openiug hot presses.

It is another object of this invention to provide unload- Patented Dec. 29, 1959 'ice ing apparatus which is of simple, inexpensive construction and adaptable for use with a variety of press types and work unit classes.

Still another object of the present invention is the provision of press unloading apparatus which may be employed to unload multi-opening presses without hazard of damaging the press.

Still a further object of the present invention is the provision of press unloading apparatus which is adaptable for use in the automatic operation of a multi-opening hot press.

The manner in which the foregoing and other objects of this invention are accomplished will be apparent from the accompanying specification and claims considered together with the drawings wherein:

Fig. 1-is a view in side elevation of the herein described press unloading apparatus illustrated in conjunction with a multiopening platen press and its associated press charger and receiver;

Fig. 2 is a fragmentary, detail plan view of the press unloading apparatus of Fig. l; and

Fig. 3 is a detail view taken along line 3 of Fig. l and illustrating particularly the engaging means used for engaging the work units in the press when unloading them therefrom.

Generally stated, the presently described press unloading apparatus is employed in conjunction with presses having a plurality of relatively movable pressure plates forming spaced openings when the plates are separated to receive and discharge work units traveling stepwise through the press in a predetermined path. The apparatus includes engaging means stationed beside the press at a first station where it is out of the travel path of the work units in the press when the latter is closed.

Drive means are connected to the engaging means for driving the same to a second station which lies in the travel path of the work units when the press is open. The engaging means thereupon engages the units and, upon being returned to its first station, contemporaneously shifts the units to advanced positions where they may be removed readily from the press.

Considering the foregoing in greater detail and with particular reference to the drawings;

In the drawing the herein described press unloader is illustrated in conjunction with a multiopening press indicated generally at 10, a press charger indicated generally at 12, and a charge receiver indicated generally at 14. These units may be of conventional construction.

Thus press 10 includes a frame on which are mounted a plurality of relatively movable pressure plates 16, 18, 20. These may be acted upon by an hydraulic cylinder, not illustrated, which presses the plates together upon being extended and separates them upon being retracted forming spaced openings into which the press charge may be introduced.

The press loader 12 which is used for charging the press may comprise a rack including vertically spaced support members 22, 24, 26 afiixed to standards 27 and substantially aligned respectively with plates 16, 18, 20 of the press when the latter is open.

The press charger is dimensioned to receive a plurality of work units 28, 30, 32. These units normally are identical with each other, and, like top unit 28, may comprise a felt 34 made up of a mixture of lignocellulose particles and adhesive sandwiched between an upper metallic caul plate 36 and a lower metallic caul plate 38. Suitable means which are well known and not illustrated are associated with the press charger for pushing the work units thereon into press 10.

The press unloading rack 14 which also is employed in conjunction with the normal operation of press 10 com-' q in prises a rack including the horizontal support members 4-0, 42, 44 fastened to suitably arranged standards one of which is indicated at 46. Angled guide plates 43, 50, 52 are fastened to the infeed ends of the support members. Rollers 54, 56, 58 are rotatably mounted between support members 40, 42, 44 and corresponding support members on the opposite side of the apparatus.

The tops of these rollers are substantially on the same horizontal plane as are the tops of press plates 16, 18, 20. Accordingly unpressed work units 23, 3t, 32 may he pushed from press charger 12 into press 1% where they are consolidated into units of predetermined thickness and density, typified by units 66), 62 and 64 of Fig. 1. After having been consolidated, the units are transferred to receiving rack 14 while a new charge is being transferred to the press from charger 12.

To assist in the unloading of the consolidated work units from press there is provided a vertical rock shaft 70 which is mounted for rotation in bearings 72. Rigid to the shaft are a plurality of vertically spaced arms 74, 76, 78, each being stationed opposite one of the spaced openings present in the press when the press is open.

Drive means are connected to shaft 7%) for moving arms 74, 76, 78 between a first station wherein the arms lie beside the work units in the press, out of the path of travel thereof and a second station wherein the arms are advanced into the openings between the press plates and into the path of travel of the work units. In the illustrated embodiment, the drive means comprise a fluid actuated cylinder, preferably an air cylinder 80, pivotally mounted by means of pin 82 between brackets 84, 86 afiixed to vertical structural members 88, 90. Cylinder 80 is supplied with air through connection 92. Its piston rod 94- has a clevis 96 mounted on its outer end and this member is connected by means of pin 98 to a crank arm 100 which, in turn, is rigid to the upper end of rock shaft 70.

Means are present on each of the arms for engaging the work units in the press. In the illustrated form of the invention, such means comprise dogging members 102, 104, 106 mounted pivotally on arms 74, 76, 78, respectively. Although various types of pivotal mountings may be employed, the desired result may be obtained by using the hinge means indicated generally 1 38, 110, and 112. Each hinge may comprise, for example, a pair of spaced knuckles 114, 116 between which the corresponding dog is mounted by means of pin 118.

Stop means are associated with each dog for limiting the degree of its angular movement. This makes possible shifting the dog from its first station beside the corresponding work unit to its second station behind the trailing edge of the work unit, the dog swinging freely during this movement, and then back to its first station, the dog being rigid during this movement so as to engage and advance the work unit. Tl is sequence is illustrated particularly in Fig. 2 where the dog is indicated in its first station in solid outline and in its second station behind the work unit in dotted outline.

The stop means employed for this purpose conveniently may comprise tabs 12%, 122, 124 which are rigid to dogs 102, 104, 106, respectively, and extend substantially at right angles thereto, overlying the respective arms to which the dogs are attached.

At the conclusion of each unloading cycle, arms 74, 76, 73 which mount the dogs come in Contact with limit switches 125 which are all in series and connected with the press actuating mechanism. As a result they prevent closure of the press unless all of the arms are in the position of Fig. 2, withdrawn from the press so that the press elements will not be damaged during the next press cycle.

As the consolidated work units are moved to advanced positions by dogs M2, 194, 106, they are engaged by suitable means for transferring them to unloading rack 14. Such means in the illustrated form comprise a plurality of rollers 172s, 128, 136, rotatably mounted on vertical ll supports 132 and driven by means of drive chain 134 which passes over idler sprockets 136, 138, 140 and engages another sprocket which is driven by a suitable motor, not illustrated.

Rolls 126, 123, 13th, are spaced only slightly beyond the leading edges of the consolidated work units in the press. Accordingly when the work units are driven forwardly by dogs N92, 104, 1 the work units ride upon rolls 126, 128, 136) and are driven by them in the direction of unloading rack 14. There they are guided by plates 4 3, 5d, 52, onto rolls 54, 56, 58, and companion rolls, which enable their transfer to the rack.

Operation The operation of the herein described press unloading apparatus is as follows:

Unconsolidated work units such as fibrous mat 34 sandwiched between caul plates 36, 33 are loaded in the usual manner on a conventional press charger 12. Press 10 is set with the plates spread apart. The work units then are transferred onto the plates 16, 18, 20 and the press closed in the usual manner.

After the press cycle is complete, the press is opened. Thereupon piston rod 94 of cylinder is extended. This rotates rock shaft 7t until arms 74, 76, 78 and dogs 102, 104-, 166 hinged thereto have been moved from the solid outline position of Fig. 2 to the dotted outline position of Fig. 2. During this movement, the dogs swing freely on their hinge mountings 108, 110, 112 and drag across the top surfaces of the work units.

The piston rod 94 of cylinder 80 then is retracted. Thereupon the dogs engage the trailing edges of the work units and are restrained from swinging movement by stop tabs 120, 122, 124. As a consequence, they push the work units toward the outfeed end of the press where they are engaged by live rolls 126, 128, 130. These in turn transfer them to the units of unloading rack 14.

Thus it will be apparent that by the present invention we have provided press unloading apparatus which is applicable to the removal of the charge from a multiopening hot press such as is used in the production of composition boards and plywood. The operation of the apparatus is fast, efiicient, and dependable. Furthermore, it is adaptable to automatic press operation even though it is of simple, inexpensive construction.

It is to be understood that the form of our invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described our invention, we claim:

1. Apparatus for advancing a work unit in a press having a plurality of relatively movable pressure plates forming spaced openings to receive the work units in a press position, comprising work unit engaging means mounted at one side of the press, and means reciprocating the work unit engaging means in a horizontal plane between first and second stations, the first station of the Work unit engaging means being disposed at the side of the press out of the travel path of the work unit and the second station thereof being disposed in the travel path of the work unit adjacent the trailing edge of the work unit in its press position, the path of travel of the work unit engaging means from the first station to the second station intersecting one corner of the trailing end of the work unit in its press position, the work unit engaging means being arranged to move freely across the said corner of the work unit in the travel thereof be tween its first and second stations and engaging the trailing edge of the work unit in the travel thereof from its second station to its first station to shift the work unit to an advanced position.

2. Apparatus for advancing a work unit in a press having a plurality of relatively movable pressure plates forming spaced openings to receive the work units in a.

press position, comprising an arm member pivotally mounted at one side of the press, means reciprocating the arm member in a horizontal plane between first and second stations, the first station of the arm being disposed at the side of the press out of the travel path of the work unit and the second station of the arm member being disposed in the horizontal travel path of the work unit adjacent the trailing edge thereof in its press position, the path of travel of the arm from the first station to the second station intersecting one corner of the trailing end of the work unit in its press position, and dog means on the arm, the dog means moving freely across the said corner of the work unit in the travel of the arm between its first and second stations and engaging the trailing edge of the work unit in the travel of the arm from its second station to its first station to shift the work unit to an advanced position.

3. Apparatus for advancing a work unit in a press having a plurality of relatively movable pressure plates forming spaced openings to receive the work units in a press position, comprising a vertically disposed rock shaft at one side of the press adjacent one end of the work unit in its press position, an arm member fixed to the shaft for reciprocating movement in a horizontal plane, and dog means pivotally mounted on the arm member and movable between first and second stations in reciprocating movement of the arm member, the first station of the dog means being disposed at the side of the press out of the travel path of the work unit and the second station of the dog means being disposed in the travel path of the work unit adjacent the trailing end thereof in its press position, the path of travel of the dog means from the first station to the second station intersecting one corner of the trailing end of the work unit in its press position, the dog means pivoting to an inoperative position to drag freely across the said corner of the work unit in its travel between first and second stations and pivoting to an operative position to engage the trailing edge of the work unit in its travel between its second and first stations to shift the work unit to an advanced position.

References Cited in the file of this patent UNITED STATES PATENTS 2,300,182 Sumner et al Oct. 27, 1942 2,685,374 Croston Aug. 3, 1954 2,726,775 Howard Dec. 13, 1955 2,775,742 Langenberg Jan. 8, 1957 2,782,904 Sangster Feb. 26, 1957 

